Swat SBT-12 v.3

12″ subwoofer · dual 2 Ω · 800 W RMS

Fs 36 HzQts 0.48Vas 0.87 ft³

Recommended box

For a sedan, one sub, 800 W. It’s the same math as the designer’s step-by-step mode, where you can fit the box to your space, vehicle and amp and get plans, a cut sheet and DXF.

Sealed

Net volume0.71 ft³ (20 L)
Qtc0.72
Fc54 Hz
F3 (−3 dB, no cabin gain)56 Hz
Example box (outside)14 9/16″ × 14 9/16″ × 9 9/16″
Open sealed box in designer

Ported

Net volume1.59 ft³ (45 L)
Tuning (Fb)32 Hz
Portslot 1 15/16 × 14 5/16″, 41 15/16″ long
Port velocity at 800 W67 ft/s
F3 (−3 dB, no cabin gain)29 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 11 3/4″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs36 Hz
Qts0.48
Qes0.522
Qms6
Vas0.87 ft³
Re (one coil)≈ 1.7 Ω
Sd≈ 76 in²
Xmax≈ 0.39″
EBP69 — sealed or ported calc.
Sensitivity, 1 W / 1 m85.4 dB calc.

General

Size12″
Voice coilsdual 2 Ω
RMS power800 W

Mounting dimensions

Ø12 11/16″cutout Ø11 5/16″mounting depth 6″magnet Ø6 11/16″
Cutout diameter11 5/16″
Mounting depth6″
Overall diameter12 11/16″
Magnet diameter6 11/16″

Only Qts is published — Qms assumed to be 6 and Qes calculated (barely affects box design).

“≈” means the value isn’t in the spec sheet and a typical value for the size is used; “calc.” means it’s calculated from the published parameters. Check the manufacturer’s spec sheet before you build.

Data sources

Other Swat 12″ models